How to Grow a Mountain

Mt. St. Helens continues to ooze. This picture shows inside the crater (that blew almost 25 years ago) with an old dome on the left and the new (and growing) dome on the right. I wonder how long before that new dome actually starts adding height back on to the mountains? (BTW - That's Mt. Rainier Adams in the distance.)

Update: Mt. Adams in the distance, not Mt. Rainier (thanks Scotty)